<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>上机练习4</title>
	</head>
	<body>
		<script>
			function Persion(name,chinese,mathscore){
				this.name=name;
				this.chinese=chinese;
				this.mathscore=mathscore;
			}
			Persion.prototype.show=function(){
				document.write("姓名为："+this.name+"<br />语文："+this.chinese
				+"<br />数学："+this.mathscore);
			}
			function Stuednt(name,chinese,mathscore,age){
				Persion.call(this,name,chinese,mathscore);
				this.age=age;
			}
			Student.prototype=new Persion();
			Student.prototype.showage=function(){
				document.write("年龄为："+this.age);
			}
			var st=new Stuednt("张三","88","95","19");
			
		</script>
	</body>
</html>
